Updated 1 July 2022
The place of trees in urban intensification
We support the goal of reducing carbon emissions in Kāpiti. This is especially challenging when there is increased growth which inevitably produces more emissions. We support increasing housing density in urban areas as a way to begin to address transport and housing emissions, but it is especially important that alongside this the district has goals, measurements and strategies to holistically reduce carbon emissions and improve the urban environment.
Many trees are being felled to make way for development, as detailed in this article, and can be observed around Kāpiti. We are campaigning for policies that recognise the importance of trees in urban areas, and will support and increase their numbers as urban intensification continues.
Services provided by trees and open spaces
Trees capture and store carbon. While it is more difficult to measure the quantity of carbon sequestered by urban trees, a hectare of new native forest sequesters 324 tonnes of carbon over 50 years and stores it indefinitely. A study by Hamburg University scientists found that 70% of carbon is captured during the last half of a tree’s life. Thus it is very important that mature trees are not felled. It would take decades for the carbon contained to be sequestered by new plantings. We emphasise that tree felling should be discouraged, but when necessary due to a tree being dead, diseased, dangerous or in the way of intensification in key areas, that several new trees should be planted to compensate.
- Trees provide shade and cooling in urban spaces.
- Trees absorb pollutants, both gaseous and particulate. Air pollution is produced by vehicles, factories, construction sites, and road works.
- Trees and open spaces support biodiversity. This is especially true if trees are set out in corridors which connect larger ‘islands’ of natural habitats.
- Trees and open spaces make a city attractive to live in or visit. The presence of trees along walkways and cycleways enhances the experience of active transport making it more likely that people with walk, cycle etc.
- Trees and open spaces increase human well-being, both aesthetically and by providing for recreation.
- Trees absorb water, reduce run off during heavy rain and prevent slips.
- Trees absorb noise.
Proposals for increasing tree canopy cover and open spaces
- Work with developers to encourage retention of trees and incorporation of trees in development plans. Where existing urban trees are cut down, more should be planted elsewhere within the development to compensate. Council itself should adopt this approach for development on land it manages too.
- Enforce rules protecting notable trees in the District Plan.
- Aim for the 3-30-300 rule. This has been developed by a professor at the University of British Columbia in Canada. It calls for (a) every citizen to be able to see 3 decent sized trees from their home and (b) there is 30% of tree cover in every neighbourhood and (c) a walking distance of 300m or less from every home to a park or green space.
- Provide guidance for urban tree planting. This could include a list of trees suitable for a certain land area and height. There is a guide specifically for native plants here.
- Regularly measure the amount of tree canopy and open spaces in the district to understand if the situation is improving or worsening
- Employ an arborist to look after trees on Council land and to advise about planting and care of vegetation.
We will be challenging Kāpiti Coast District Council to adopt these policies.
The Parliamentary Commissioner for the Environment released this report on the importance of urban green spaces on 17 March 2023.